RPi boot path includes the GPU/VPU, which runs a binary blob based on an older version of ThreadX RTOS, whose upstream is now called Azure RTOS ThreadX. Work on an open-source replacement has been slowly inching forward for a few years.
Arm, including the quirky RPi, is not comparable in openness to x86 general purpose desktops, which were a happy confluence of accidents, determined individuals and scrappy businesses. That is still worth defending, if only to slow the slide backwards.
M1 Macs have a unique take on hardware security that can co-exist with general-purpose computing for open-source Linux, and Apple's vertical integration. https://archive.fosdem.org/2022/schedule/speaker/xeno_kovah/. Hopefully Asahi Linux will succeed in creating a relatively maintainable port for multiple generations of Apple Silicon.
Arm, including the quirky RPi, is not comparable in openness to x86 general purpose desktops, which were a happy confluence of accidents, determined individuals and scrappy businesses. That is still worth defending, if only to slow the slide backwards.
M1 Macs have a unique take on hardware security that can co-exist with general-purpose computing for open-source Linux, and Apple's vertical integration. https://archive.fosdem.org/2022/schedule/speaker/xeno_kovah/. Hopefully Asahi Linux will succeed in creating a relatively maintainable port for multiple generations of Apple Silicon.